采用FactSage8.2 热力学计算软件对铸造奥氏体不锈钢CK3MCuN的平衡凝固及冷却过程相变以及基于 Scheil-Gulliver 冷却模式下的非平衡凝固过程展开研究。 结果表明， 平衡凝固过程中Fe、Ni元素易于奥氏体枝晶干偏 聚，Cr、Cu、Mo、C 及 N 元素随着凝固过程的进行易于枝晶间富集， 并且Cu偏析逐渐减弱，Fe、Cr及Ni的偏析逐渐增 强；非平衡凝固过程中Fe、Ni元素为负偏析，Cr、Mo、Cu、N及C为正偏析，其中Cr、Mo元素在凝固末期的残余液相中 偏析非常严重。 平衡转变过程中析出主要的金属间相为σ与Laves相，其最大析出量分别为18.1%与12%(质量分数)； 非平衡凝固过程析出主要的金属间相为σ相，其最大析出量为0.7%。 平衡转变过程：Mo促进σ与Laves相的形成，N 促进Cr2 N 析出、抑制σ与M23 C6碳化物的形成，Cu有利于ε-Cu相的形成；非平衡凝固过程：Mo促进σ相与δ铁素体 的形成，N促进Cr2 N析出、抑制δ铁素体形成，Cu能够抑制δ铁素体的形成，但是对Cr2 N和σ相基本没有影响

The equilibrium solidification and cooling phase transition of cast austenitic stainless steel CK3MCuN and the non-equilibrium solidification process in the Scheil-Gulliver cooling mode were investigated via FactSage8.2 thermodynamic calculation software. The results indicate that during the equilibrium solidification process, Fe and Ni are easily isolated by austenitic dendrites, while Cr, Cu, Mo, C and N are easily enriched in the interdendritic region. The interdendritic segregation of Cu gradually weakens, while the segregation of Fe, Cr and Ni gradually increases. In the non-equilibrium solidification process, Fe and Ni undergo negative segregation, while Cr, Mo, Cu, N and C undergo positive segregation, and Cr and Mo undergo very severe segregation in the residual liquid phase at the end of solidification. The main intermetallic phases precipitated during the equilibrium transition process are the sigma phase and Laves phase, with maximum precipitated phase contents of 18.1 wt. % and 12 wt. %, respectively, while the main intermetallic phase precipitated during the non-equilibrium solidification process is the sigma phase, with a maximum precipitated phase content of 0.7 wt. %. In the equilibrium transition process, Mo promotes the formation of the sigma phase and Laves phase, N promotes the precipitation of Cr2 N and inhibits the formation of the sigma phase and M23 C6 carbide, and Cu favors the formation of the ε-Cu phase. In the non-equilibrium solidification process, Mo can promote the formation of the sigma phase and δ-ferrite, N can promote the precipitation of Cr2 N and inhibit the formation of δ-ferrite simultaneously, and Cu can inhibit the formation of δ-ferrite but has little effect on Cr2 N or the sigma phase.